US20190257413A1 - Control method and control device of continuously variable transmission - Google Patents
Control method and control device of continuously variable transmission Download PDFInfo
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- US20190257413A1 US20190257413A1 US16/329,531 US201716329531A US2019257413A1 US 20190257413 A1 US20190257413 A1 US 20190257413A1 US 201716329531 A US201716329531 A US 201716329531A US 2019257413 A1 US2019257413 A1 US 2019257413A1
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- 230000005540 biological transmission Effects 0.000 title claims abstract description 15
- 238000000034 method Methods 0.000 title claims abstract description 11
- 238000004891 communication Methods 0.000 claims description 3
- 230000033001 locomotion Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 238000005461 lubrication Methods 0.000 description 4
- 238000001816 cooling Methods 0.000 description 2
- 230000009931 harmful effect Effects 0.000 description 2
- 238000001514 detection method Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
- F16H61/0021—Generation or control of line pressure
- F16H61/0025—Supply of control fluid; Pumps therefore
- F16H61/0031—Supply of control fluid; Pumps therefore using auxiliary pumps, e.g. pump driven by a different power source than the engine
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
- F16H61/66—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing specially adapted for continuously variable gearings
- F16H61/662—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing specially adapted for continuously variable gearings with endless flexible members
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H2306/00—Shifting
- F16H2306/36—Filling the dead volume of actuators
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H2312/00—Driving activities
- F16H2312/20—Start-up or shut-down
Definitions
- the present invention relates to control of a continuously variable transmission.
- JP2008-240894A1 discloses a hydraulic circuit of a continuously variable transmission including a source pressure oil pump adapted to pump up oil from an oil pan and generate line pressure serving as source pressure for shift, and an electric oil pump for shift.
- a source pressure oil pump adapted to pump up oil from an oil pan and generate line pressure serving as source pressure for shift
- an electric oil pump for shift In the hydraulic circuit described in the above document, communication is provided between a primary pulley oil chamber and a secondary pulley oil chamber, and the electric oil pump is placed in a shift oil passage connected to an oil passage of the line pressure.
- shift control is performed.
- a control method may be capable of suppressing a harmful effect caused by start of shift control in a no-oil state, such as noise generation due to the air entrainment as described above.
- a control method of a continuously variable transmission comprising
- FIG. 1 is a schematic configuration diagram of a vehicle.
- FIG. 2 is a schematic configuration diagram of a hydraulic circuit.
- FIG. 3 is a flowchart showing a control routine of a first embodiment.
- FIG. 4 is a timing chart of a case where the control routine of FIG. 3 is executed.
- FIG. 5 is a timing chart of a case where a modified example of the control routine of FIG. 3 is executed.
- FIG. 6 is a flowchart showing a control routine of a second embodiment.
- FIG. 7 is a correction amount table of a SEC side oil pressure command value.
- FIG. 8 is a timing chart of a case where the control routine of FIG. 6 is executed.
- FIG. 9 is a table used for calculating the SEC side oil pressure command value.
- FIG. 10 is a flowchart showing a control routine of a third embodiment.
- FIG. 11 is a timing chart of a case where the control routine of FIG. 10 is executed.
- FIG. 12 is a timing chart of a case where a SEC side oil pressure command value is corrected in the third embodiment.
- FIG. 1 is a schematic configuration diagram of a vehicle.
- the vehicle includes an engine 1 , a torque converter 2 having a lock-up clutch 2 a, a forward/reverse switching mechanism 3 , a variator 4 , a final reduction mechanism 5 , drive wheels 6 , and a hydraulic circuit 100 .
- the engine 1 is a drive source of the vehicle. An output of the engine 1 is transmitted to the drive wheels 6 via the torque converter 2 , the forward/reverse switching mechanism 3 , the variator 4 , and the final reduction mechanism 5 . Therefore, the variator 4 is provided in a motive power transmission route through which motive power is transmitted from the engine 1 to the drive wheels 6 together with the torque converter 2 , the forward/reverse switching mechanism 3 , and the final reduction mechanism 5 .
- the forward/reverse switching mechanism 3 is provided between the torque converter 2 and the variator 4 in the above motive power transmission route.
- the forward/reverse switching mechanism 3 switches the rotation direction of inputted rotation between the forward rotation direction corresponding to a forward run and the reverse rotation direction corresponding to a reverse run.
- the forward/reverse switching mechanism 3 includes a forward clutch 31 and a reverse brake 32 .
- the forward clutch 31 is engaged in a case where the rotation direction is the forward rotation direction.
- the reverse brake 32 is engaged in a case where the rotation direction is the reverse rotation direction.
- One of the forward clutch 31 and the reverse brake 32 can be formed as a clutch adapted to turn rotation on and off between the engine 1 and the variator 4 .
- the variator 4 has a primary pulley 41 , a secondary pulley 42 , and a belt 43 looped over the primary pulley 41 and the secondary pulley 42 .
- the term “primary” will also be referred to as “PRI”
- the term “secondary” will also be referred to as “SEC.”
- the variator 4 changes a loop diameter of the belt 43 (hereinafter, also simply referred to as the “loop diameter”) by changing groove widths of the PRI pulley 41 and the SEC pulley 42 , and forms a belt continuously variable transmission mechanism adapted to perform shift.
- the PRI pulley 41 includes a fixed pulley 41 a and a movable pulley 41 b.
- a controller 10 controlling an oil amount supplied to a PRI pulley oil pressure camber 41 c, the movable pulley 41 b is activated and the groove width of the PRI pulley 41 is changed.
- the SEC pulley 42 includes a fixed pulley 42 a and a movable pulley 42 b.
- the controller 10 controlling SEC pressure which is pulley pressure supplied to a SEC pulley oil pressure chamber 42 c, the movable pulley 42 b is activated and the groove width of the SEC pulley 42 is changed.
- Pulley pressure supplied to the PRI pulley oil pressure chamber 41 c is referred to as PRI pressure.
- the belt 43 is looped over a V-shaped sheave surface formed by the fixed pulley 41 a and the movable pulley 41 b of the PRI pulley 41 , and a V-shaped sheave surface formed by the fixed pulley 42 a and the movable pulley 42 b of the SEC pulley 42 .
- the final reduction mechanism 5 transmits output rotation from the variator 4 to the drive wheels 6 .
- the final reduction mechanism 5 has plural gear trains and differential gears.
- the final reduction mechanism 5 rotates the drive wheels 6 via an axle.
- the hydraulic circuit 100 supplies oil pressure to the variator 4 , specifically, to the PRI pulley 41 and the SEC pulley 42 .
- the hydraulic circuit 100 also supplies the oil pressure to the forward/reverse switching mechanism 3 , the lock-up clutch 2 a, and a lubrication system and a cooling system (not shown).
- the hydraulic circuit 100 is formed as follows.
- FIG. 2 is a schematic configuration diagram of the hydraulic circuit 100 .
- the hydraulic circuit 100 includes a source pressure oil pump 101 , a line pressure adjusting valve 102 , a pressure reduction valve 103 , a line pressure solenoid valve 104 , a forward/reverse switching mechanism solenoid valve 105 , a shift circuit pressure solenoid valve 107 , a manual valve 108 , a line pressure oil passage 109 , a low pressure system control valve 130 , a shift circuit 110 , and a line pressure electric oil pump 111 .
- the solenoid valve will be referred to as the SOL.
- the source pressure oil pump 101 is a mechanical oil pump to be driven by motive power of the engine 1 .
- the source pressure oil pump 101 is connected to the line pressure adjusting valve 102 , the pressure reduction valve 103 , and the shift circuit pressure SOL 107 and the shift circuit 110 via the line pressure oil passage 109 .
- the line pressure oil passage 109 forms an oil passage of line pressure.
- the line pressure is oil pressure serving as source pressure of the PRI pressure and the SEC pressure.
- the line pressure electric oil pump 111 is driven by an electric motor 117 .
- the line pressure electric oil pump 111 is operated for supplying the line pressure for example in a case where the engine 1 is stopped by idling stop control and accordingly the source pressure oil pump 101 is stopped.
- the line pressure adjusting valve 102 generates the line pressure by adjusting the oil pressure generated by the oil pump 101 .
- the generation of the line pressure by the oil pump 101 includes generation of the line pressure on the basis of such an action of the line pressure adjusting valve 102 .
- Oil released by the line pressure adjusting valve 102 at the time of pressure adjustment is supplied to the lock-up clutch 2 a, the lubrication system, and the cooling system via the low pressure system control valve 130 .
- the pressure reduction valve 103 reduces the line pressure.
- the oil pressure reduced by the pressure reduction valve 103 is supplied to the line pressure SOL 104 and the forward/reverse switching mechanism SOL 105 .
- the line pressure SOL 104 is a linear solenoid valve and generates control oil pressure corresponding to a control electric current.
- the control oil pressure generated by the line pressure SOL 104 is supplied to the line pressure adjusting valve 102 , and the line pressure adjusting valve 102 is activated in accordance with the control oil pressure generated by the line pressure SOL 104 to perform pressure adjustment. Therefore, it is possible to set a command value of line pressure PL by the control electric current to the line pressure SOL 104 .
- the forward/reverse switching mechanism SOL 105 is a linear solenoid valve and generates oil pressure corresponding to a control electric current.
- the oil pressure generated by the forward/reverse switching mechanism SOL 105 is supplied to the forward clutch 31 and the reverse brake 32 via the manual valve 108 activated in accordance with operation of a driver.
- the shift circuit pressure SOL 107 is a linear solenoid valve and generates oil pressure to be supplied to the shift circuit 110 in accordance with a control electric current. Therefore, it is possible to set a command value of shift circuit pressure by the control electric current to the shift circuit pressure SOL 107 .
- the shift circuit pressure generated by the shift circuit pressure SOL 107 is supplied to a shift oil passage 106 .
- the shift circuit pressure may be generated by a SOL adapted to generate control oil pressure corresponding to a control electric current, and a pressure adjusting valve adapted to generate control circuit pressure from the line pressure PL in accordance with the control oil pressure generated by the SOL.
- the shift circuit 110 includes a shift oil passage 106 connected to the line pressure oil passage 109 via the shift circuit pressure SOL 107 , and a shift oil pump 112 placed in the shift oil passage 106 .
- the shift oil passage 106 provides communication between the PRI pulley oil pressure chamber 41 c and the SEC pulley oil pressure chamber 42 c.
- the shift oil pump 112 is an electric oil pump to be driven by an electric motor 113 .
- the electric motor 113 is controlled by the controller 10 via an inverter 114 .
- the rotation direction of the shift oil pump 112 is switchable between the forward direction and the reverse direction.
- the forward direction mentioned above is the direction in which the oil is fed from the SEC pulley oil pressure chamber 42 c side to the PRI pulley oil pressure chamber 41 c side.
- the reverse direction is the direction in which the oil is fed from the PRI pulley oil pressure chamber 41 c side to the SEC pulley oil pressure chamber 42 c side.
- the oil is supplied from the line pressure oil passage 109 to the shift oil passage 106 in such a manner that oil pressure of the shift oil passage 106 on the SEC pulley oil pressure chamber 42 c side (hereinafter, also referred to as the “SEC side”) of the shift oil pump 112 (hereinafter, also referred to as the “SEC side oil pressure”) is not less than the command value of the shift circuit pressure.
- the command value of the shift circuit pressure is set in consideration with prevention of slip of the belt 43 , etc.
- Oil pressure of the shift oil passage 106 on the PRI pulley oil pressure chamber 41 c side (hereinafter, also referred to as the “PRI side”) of the shift oil pump 112 will also be referred to as the PRI side oil pressure.
- the SEC side oil pressure is increased by an inflow of the oil flowing out of the PRI pulley oil pressure chamber 41 c, the SEC side oil pressure is controlled not to exceed the command value by the shift circuit pressure SOL 107 . That is, in a case where the SEC side oil pressure exceeds the command value, the oil is discharged from the shift oil passage 106 via the shift circuit pressure SQL 107 . Meanwhile, in a case where the SEC side oil pressure is less than the command value, the oil flows in from the line pressure oil passage 109 via the shift circuit pressure SOL 107 .
- shift is performed by the shift oil pump 112 controlling a flow of the oil into and from the PRI pulley oil pressure chamber 41 c.
- An outline of shift control will be described later.
- the vehicle further includes the controller 10 .
- the controller 10 is an electronic control device, and signals from a sensor and switch group 11 are inputted to the controller 10 .
- the controller 10 is formed by a microcomputer including a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), and an input/output interface (I/O interface).
- the controller 10 may be formed by plural microcomputers.
- the sensor and switch group 11 includes an accelerator pedal opening sensor adapted to detect an accelerator pedal opening of the vehicle, a brake sensor adapted to detect brake pedal force of the vehicle, a vehicle speed sensor adapted to detect vehicle speed Vsp, and an engine rotation speed sensor adapted to detect rotation speed NE of the engine 1 .
- the sensor and switch group 11 further includes, for example, a PRI pressure sensor 115 adapted to detect the PRI pressure, a SEC pressure sensor 116 adapted to detect the SEC pressure, a PRI rotation speed sensor 120 adapted to detect input side rotation speed of the PRI pulley 41 , a SEC rotation speed sensor 121 adapted to detect output side rotation speed of the SEC pulley 42 , a pump rotation speed sensor 118 adapted to detect rotation speed of the shift oil pump 112 , and an oil temperature sensor 119 adapted to detect a temperature of the oil.
- the signals from the sensor and switch group 11 may be inputted to the controller 10 via other controllers, for example. The same is applied to signals of information, etc. generated by other controllers on the basis of the signals from the sensor and switch group 11 .
- the controller 10 controls the hydraulic circuit 100 on the basis of the signals from the sensor and switch group 11 . Specifically, the controller 10 controls the line pressure SOL 104 and the shift circuit 110 shown in FIG. 2 . The controller 10 is formed to further control the forward/reverse switching mechanism SOL 105 and the shift circuit pressure SOL 107 .
- the controller 10 Upon controlling the line pressure SOL 104 , the controller 10 applies a control electric current corresponding to the command value of the line pressure PL to the line pressure SOL 104 .
- the controller 10 When executing the shift control, the controller 10 sets a target speed ratio on the basis of the signals from the sensor and switch group 11 . Once the target speed ratio is determined, loop dimeters (target loop diameters) of the pulleys 41 , 42 for realizing the target speed ratio are determined. Once the target loop diameters are determined, groove widths (target groove widths) of the pulleys 41 , 42 for realizing the target loop diameters are determined.
- the movable pulley 41 b of the PRI pulley 41 is moved in accordance with the inflow and the outflow of the oil to and from the PRI pulley oil pressure chamber 41 c by the shift oil pump, and accordingly, the movable pulley 42 b of the SEC pulley 42 is also moved. That is, there is a correlation between a movement amount of the movable pulley 41 b of the PRI pulley 41 and a movement amount of the movable pulley 42 b of the SEC pulley 42 .
- the controller 10 operates the shift oil pump 112 in such a manner that a position of the movable pulley 41 b of the PRI pulley 41 is a position corresponding to the target speed ratio. Whether or not the movable pulley 41 b is at a desired position is determined by calculating an actual speed ratio from detection values of the PRI rotation speed sensor 120 and the SEC rotation speed sensor 121 and determining whether or not the actual speed ratio matches with the target speed ratio.
- the operation of the shift oil pump 112 by the controller 10 is not limited to the time of shift. Even in a case where the target speed ratio is not changed but in a case where the oil is leaked out of the pulley oil pressure chambers 41 c, 42 c and the actual speed ratio is changed, the controller 10 operates the shift oil pump 112 . In the first embodiment, such control for maintaining the target speed ratio is included in the shift control.
- the shift control of the first embodiment is feedback control of bringing the position of the movable pulley 41 b of the PRI pulley 41 to a target position.
- An object to be controlled in the feedback control is not the oil pressure of the pulley oil pressure chambers 41 c, 42 c but the groove width of the PRI pulley 41 , in other words, the position of the movable pulley 41 b.
- a sensor adapted to detect the position of the movable pulley 41 b may be provided to determine whether or not the movable pulley 41 b is at a position corresponding to the target speed ratio.
- both the source pressure oil pump 101 and the line pressure electric oil pump 111 are stopped.
- no oil pressure is supplied to the line pressure oil passage 109 and the SEC pulley oil pressure chamber 42 c. Therefore, for example, in a case where a long time passes after an end of driving the vehicle, the oil may be removed from the oil passages of the hydraulic circuit in a so-called no-oil state.
- the shift oil pump 112 is operated in a state where the oil is not filled in the line pressure oil passage 109 and the shift oil passage 106 .
- the shift oil pump 112 performs so-called idle pumping, and noises are generated due to the air entrainment described above.
- the shift oil pump 112 is operated in the no-oil state, lubrication of a bearing portion becomes insufficient and there is a possibility that the shift oil pump 112 is deteriorated.
- the controller 10 executes control to be described below.
- FIG. 3 is a flowchart showing a control routine of the hydraulic circuit 100 to be executed by the controller 10 at the time of start-up of the engine.
- the control routine is executed when the engine 1 is started up.
- Step S 100 the controller 10 determines whether or not the oil is filled in the shift oil passage 106 on the SEC side by a method to be described later.
- the controller 10 repeats the determination of Step S 100 until the oil is filled in the shift oil passage 106 on the SEC side, and when the oil is filled, starts up the shift oil pump 112 in Step S 110 . That is, in Step S 100 , by not permitting the operation of the shift oil pump 112 until the oil is filled in the shift oil passage 106 on the SEC side, the controller 10 restricts the operation of the shift oil pump 112 .
- Specific examples of the judging method of Step S 100 include two examples as follows.
- the shift oil pump 112 is rotated by an oil pressure difference between the SEC side and the PRI side without being driven by the electric motor 113 .
- the controller 10 determines that the oil is filled in the shift oil passage 106 on the SEC side.
- the threshold value 1 is set to be a value with which rotation of the shift oil pump 112 is obviously recognizable, for example, a few [rpm]. Theoretically, start of rotation of a rotation shaft of the shift oil pump 112 is required to be detected. Thus, a further smaller value may be set. However, in reality, the rotation shaft of the shift oil pump 112 may be moved by vibration of the vehicle, etc. Thus, in order to prevent erroneous determination caused by detecting motion due to such vibration of the vehicle, etc., the threshold value 1 of the above magnitude is set.
- FIG. 4 is a timing chart of a case where the determination of the first example is performed.
- the SEC side actual oil pressure is increased.
- the controller 10 determines that the oil is filled in the shift oil passage 106 on the SEC side.
- the threshold value 2 is set to be a value with which that the increase of the SEC side actual oil pressure is obviously recognizable.
- the threshold value 2 is set to have an enough magnitude in order to prevent erroneous determination as well as the threshold value 1.
- FIG. 5 is a timing chart of a case where the determination of the second example is performed.
- Both motions of the source oil pump 101 and the shift oil pump 112 and changes in the SEC side actual oil pressure and the PRI side actual oil pressure are the same as FIG. 4 .
- the basis of determining the start of the operation of the shift oil pump 112 is the SEC side actual oil pressure being higher than the threshold value 2 at the timing T 2 .
- the operation of the shift oil pump 112 is restricted until the oil is filled in the shift oil passage 106 on the SEC pulley oil pressure chamber 42 c side of the shift oil pump (electric oil pump) 112 .
- the shift oil pump 112 is not rotated in the no-oil state, and it is possible to suppress generation of noises due to air entrainment and deterioration of the shift oil pump 112 due to rotation in a no-lubrication state.
- the operation of the shift oil pump 112 is permitted. That is, it is determined whether or not the oil is filled in the shift oil passage 106 on the SEC pulley oil pressure chamber 42 c side of the shift oil pump 112 on the basis of the rotation speed of the shift oil pump 112 . Thereby, even if the hydraulic circuit 100 does not include the SEC pressure sensor 116 , it is possible to make proper determination.
- the operation of the shift oil pump 112 is permitted. That is, it is determined whether or not the oil is filled in the shift oil passage 106 on the SEC pulley oil pressure chamber 42 c side of the shift oil pump 112 on the basis of the pressure of the oil passage. Thus, it is possible to make precise determination.
- the second embodiment is similar to the first embodiment in a point that an operation of a shift oil pump 112 is restricted until oil is filled in a shift oil passage 106 on the SEC side.
- the second embodiment is different from the first embodiment in a point that a SEC side oil pressure command value is corrected while the operation of the shift oil pump 112 is restricted.
- this different point will be mainly described.
- a controller 10 sets a target speed ratio on the basis of signals from a sensor and switch group 11 , and sets a SEC side oil pressure command value corresponding to the target speed ratio.
- the more the SEC side oil pressure command value is increased the more an amount of oil flowing into the shift oil passage 106 via a shift circuit pressure solenoid valve 107 is increased and the more a time to the oil filling in the shift oil passage 106 on the SEC side is shortened.
- a time to restrict the operation of the shift oil pump 112 is shortened.
- FIG. 6 is a flowchart showing a control routine of a hydraulic circuit 100 to be executed by the controller 10 in the second embodiment.
- Step S 200 the controller 10 calculates a basic SEC side oil pressure command value.
- the basic SEC side oil pressure command value is the SEC side oil pressure command value corresponding to the target speed ratio.
- Step S 210 the controller 10 determines whether or not the oil is filled in the shift oil passage 106 on the SEC side. Contents and a method of determination are the same as Step S 100 of FIG. 3 .
- the controller 10 executes processing of Step S 210 in a case where the oil is filled in the shift oil passage 106 on the SEC side, and executes processing of Step S 220 in a case where the oil is not filled.
- Step S 220 the controller 10 makes correction to increase the basic SEC side oil pressure command value, and makes the value after the correction a SEC side oil pressure command value.
- a table in which the lower an oil temperature is, the larger a correction amount is set as shown in FIG. 7 is created in advance and stored in the controller 10 , and the controller 10 adds the correction amount determined on the basis of the table to the basic SEC side oil pressure command value.
- Step S 230 the controller 10 restores the SEC side oil pressure command value to the basic SEC side oil pressure command value calculated in Step S 200 .
- the controller 10 starts up the shift oil pump 112 in Step S 240 .
- FIG. 8 is a timing chart of a case where the control described above is executed. Both motions of a source oil pump 101 and the shift oil pump 112 and changes in SEC side actual oil pressure and PRI side actual oil pressure are the same as FIG. 4 .
- the reference sign P 1 in the figure denotes the basic SEC side oil pressure command value, and the reference sign P 2 denotes a PRI side oil pressure command value.
- the SEC side oil pressure command value is gradually increased by repeating the correction.
- a gap between the timing T 1 and the timing T 2 is shorter than a case where the basic SEC side oil pressure command value is not increased and corrected.
- the SEC side oil pressure command value is restored to the basic SEC side oil pressure command value at the timing T 2 .
- Step S 220 of FIG. 6 the SEC side oil pressure command value is set between the timing T 1 and the timing T 2 by correcting the basic SEC side oil pressure command value.
- the present invention is not limited to this.
- a table in which the SEC side oil pressure command value is set in accordance with the oil temperature as shown in FIG. 9 may be created in advance and stored in the controller 10 , and the controller 10 may directly calculate the SEC side oil pressure command value from the table.
- the case where the SEC side oil pressure command value is gradually increased from the timing T 1 to the timing T 2 is described above.
- the present invention is not limited to this.
- the SEC side oil pressure command value may be set to be the SEC side oil pressure command value of the timing T 2 of FIG. 8 and this may be maintained to the timing T 2 .
- target oil pressure of the shift oil passage 106 on the SEC pulley oil pressure chamber 42 c side of the shift oil pump 112 is set to be higher than a case where the operation of the shift oil pump 112 is not restricted.
- increasing speed of the SEC pressure is increased.
- the time to restrict the operation of the shift oil pump 112 is shortened more than a case where the target oil pressure is not increased.
- the lower the oil temperature is, the higher the target oil pressure while the operation of the shift oil pump 112 is restricted is set.
- the lower the temperature is, the greater friction of the pumps 101 , 112 is.
- the source pressure is more increased.
- the operation of the shift oil pump 112 is restricted until the oil is filled in the shift oil passage 106 on the SEC side. Meanwhile, in the third embodiment, after oil is filled in a shift oil passage 106 on the SEC side, an operation of a shift oil pump 112 is further restricted until oil pressure of the shift oil passage 106 on the PRI side reaches predetermined pressure.
- FIG. 10 is a flowchart showing a control routine of the third embodiment described above.
- Step S 300 a controller 10 determines whether or not actual oil pressure of the shift oil passage 106 on the PRI side becomes higher than a threshold value 3.
- the threshold value 3 is PRI pressure determined on the basis of a target speed ratio.
- the controller 10 starts up the shift oil pump 112 in Step S 310 .
- FIG. 11 is a timing chart of a case where the control routine of FIG. 10 is executed.
- SEC side actual oil pressure starts to be increased at timing T 2 .
- the shift oil pump 112 starts to be rotated by a pressure difference between the SEC side and the PRI side.
- the shift oil pump 112 is rotated by the pressure difference described above.
- rotation speed of the shift oil pump 112 is also increased.
- PRI side actual oil pressure reaches the PRI pressure (threshold value 3) determined on the basis of the target speed ratio at timing T 3 , the controller 10 starts up the shift oil pump 112 .
- correction of SEC side command oil pressure may be performed as well as the second embodiment. In this case, as shown in FIG. 12 , the correction of the SEC side command oil pressure is continued until the timing T 3 .
- the operation of the shift oil pump 112 is restricted until the actual oil pressure of the shift oil passage 106 on the PRI pulley oil pressure chamber 41 c side of the shift oil pump 112 reaches command oil pressure. Thereby, it is possible to reduce the electric power consumed by the shift oil pump 112 until the PRI pressure is increased to the pressure determined on the basis of the target speed ratio.
- the configuration in which as an oil pump adapted to supply source pressure, the mechanical oil pump (source pressure oil pump 101 ) and the electric oil pump (line pressure electric oil pump 111 ) are used together is described.
- the mechanical oil pump source pressure oil pump 101
- the electric oil pump line pressure electric oil pump 111
- any one of the oil pumps may be provided.
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Abstract
Description
- This application is a national stage application of PCT Application No. PCT/JP2017/028628 filed Aug. 7, 2017, and claims priority to Japanese Patent Application No. 2016-166760 filed on Aug. 29, 2016 in the Japan Patent Office, the entire disclosure of which are incorporated herein by reference in their entirety.
- The present invention relates to control of a continuously variable transmission.
- JP2008-240894A1 discloses a hydraulic circuit of a continuously variable transmission including a source pressure oil pump adapted to pump up oil from an oil pan and generate line pressure serving as source pressure for shift, and an electric oil pump for shift. In the hydraulic circuit described in the above document, communication is provided between a primary pulley oil chamber and a secondary pulley oil chamber, and the electric oil pump is placed in a shift oil passage connected to an oil passage of the line pressure. In the hydraulic circuit described in the above document, by adjusting a flow of the oil into and from the primary pulley oil chamber by the electric oil pump, shift control is performed.
- In a continuously variable transmission including the hydraulic circuit described in the above document, there is a need for filling the oil in the shift oil passage for performing the shift control. Therefore, when the hydraulic circuit is in a state where the oil is removed, the so-called no-oil state and an engine is started up and the shift control is started, so-called air entrainment occurs in the electric oil pump until the oil is filled in the shift oil passage, and noises are generated.
- However, the above document does not describe control in a case where the engine is started up in the no-oil state.
- A control method according to one or more embodiments of the present invention may be capable of suppressing a harmful effect caused by start of shift control in a no-oil state, such as noise generation due to the air entrainment as described above.
- According to one or more embodiments of the present invention, a control method of a continuously variable transmission, comprising
-
- supplying oil pressure to a secondary pulley oil chamber by a source pressure oil pump, and controlling an flow of oil into and from a primary pulley oil chamber by an electric oil pump arranged in an oil passage between the primary pulley oil chamber and the secondary pulley oil chamber is provided. In the control method of a continuously variable transmission, after start-up of the source pressure oil pump, an operation of the electric oil pump is restricted until the oil is filled in the oil passage on the secondary pulley oil chamber side of the electric oil pump.
-
FIG. 1 is a schematic configuration diagram of a vehicle. -
FIG. 2 is a schematic configuration diagram of a hydraulic circuit. -
FIG. 3 is a flowchart showing a control routine of a first embodiment. -
FIG. 4 is a timing chart of a case where the control routine ofFIG. 3 is executed. -
FIG. 5 is a timing chart of a case where a modified example of the control routine ofFIG. 3 is executed. -
FIG. 6 is a flowchart showing a control routine of a second embodiment. -
FIG. 7 is a correction amount table of a SEC side oil pressure command value. -
FIG. 8 is a timing chart of a case where the control routine ofFIG. 6 is executed. -
FIG. 9 is a table used for calculating the SEC side oil pressure command value. -
FIG. 10 is a flowchart showing a control routine of a third embodiment. -
FIG. 11 is a timing chart of a case where the control routine ofFIG. 10 is executed. -
FIG. 12 is a timing chart of a case where a SEC side oil pressure command value is corrected in the third embodiment. - Hereinafter, embodiments of the present invention will be described with reference to the attached drawings. In embodiments of the invention, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to one of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid obscuring the invention.
-
FIG. 1 is a schematic configuration diagram of a vehicle. The vehicle includes anengine 1, a torque converter 2 having a lock-up clutch 2 a, a forward/reverse switching mechanism 3, avariator 4, afinal reduction mechanism 5,drive wheels 6, and ahydraulic circuit 100. - The
engine 1 is a drive source of the vehicle. An output of theengine 1 is transmitted to thedrive wheels 6 via the torque converter 2, the forward/reverse switching mechanism 3, thevariator 4, and thefinal reduction mechanism 5. Therefore, thevariator 4 is provided in a motive power transmission route through which motive power is transmitted from theengine 1 to thedrive wheels 6 together with the torque converter 2, the forward/reverse switching mechanism 3, and thefinal reduction mechanism 5. - The forward/
reverse switching mechanism 3 is provided between the torque converter 2 and thevariator 4 in the above motive power transmission route. The forward/reverse switching mechanism 3 switches the rotation direction of inputted rotation between the forward rotation direction corresponding to a forward run and the reverse rotation direction corresponding to a reverse run. - Specifically, the forward/
reverse switching mechanism 3 includes aforward clutch 31 and areverse brake 32. Theforward clutch 31 is engaged in a case where the rotation direction is the forward rotation direction. Thereverse brake 32 is engaged in a case where the rotation direction is the reverse rotation direction. One of theforward clutch 31 and thereverse brake 32 can be formed as a clutch adapted to turn rotation on and off between theengine 1 and thevariator 4. - The
variator 4 has aprimary pulley 41, asecondary pulley 42, and abelt 43 looped over theprimary pulley 41 and thesecondary pulley 42. Hereinafter, the term “primary” will also be referred to as “PRI,” and the term “secondary” will also be referred to as “SEC.” Thevariator 4 changes a loop diameter of the belt 43 (hereinafter, also simply referred to as the “loop diameter”) by changing groove widths of thePRI pulley 41 and theSEC pulley 42, and forms a belt continuously variable transmission mechanism adapted to perform shift. - The PRI
pulley 41 includes afixed pulley 41 a and amovable pulley 41 b. By acontroller 10 controlling an oil amount supplied to a PRI pulleyoil pressure camber 41 c, themovable pulley 41 b is activated and the groove width of thePRI pulley 41 is changed. - The SEC
pulley 42 includes afixed pulley 42 a and amovable pulley 42 b. By thecontroller 10 controlling SEC pressure which is pulley pressure supplied to a SEC pulleyoil pressure chamber 42 c, themovable pulley 42 b is activated and the groove width of theSEC pulley 42 is changed. Pulley pressure supplied to the PRI pulleyoil pressure chamber 41 c is referred to as PRI pressure. - The
belt 43 is looped over a V-shaped sheave surface formed by thefixed pulley 41 a and themovable pulley 41 b of thePRI pulley 41, and a V-shaped sheave surface formed by thefixed pulley 42 a and themovable pulley 42 b of theSEC pulley 42. - The
final reduction mechanism 5 transmits output rotation from thevariator 4 to thedrive wheels 6. Thefinal reduction mechanism 5 has plural gear trains and differential gears. Thefinal reduction mechanism 5 rotates thedrive wheels 6 via an axle. - The
hydraulic circuit 100 supplies oil pressure to thevariator 4, specifically, to thePRI pulley 41 and theSEC pulley 42. Thehydraulic circuit 100 also supplies the oil pressure to the forward/reverse switching mechanism 3, the lock-up clutch 2 a, and a lubrication system and a cooling system (not shown). Specifically, thehydraulic circuit 100 is formed as follows. -
FIG. 2 is a schematic configuration diagram of thehydraulic circuit 100. Thehydraulic circuit 100 includes a sourcepressure oil pump 101, a linepressure adjusting valve 102, apressure reduction valve 103, a linepressure solenoid valve 104, a forward/reverse switchingmechanism solenoid valve 105, a shift circuitpressure solenoid valve 107, amanual valve 108, a linepressure oil passage 109, a low pressuresystem control valve 130, ashift circuit 110, and a line pressure electric oil pump 111. Hereinafter, the solenoid valve will be referred to as the SOL. - The source
pressure oil pump 101 is a mechanical oil pump to be driven by motive power of theengine 1. The sourcepressure oil pump 101 is connected to the linepressure adjusting valve 102, thepressure reduction valve 103, and the shiftcircuit pressure SOL 107 and theshift circuit 110 via the linepressure oil passage 109. The linepressure oil passage 109 forms an oil passage of line pressure. The line pressure is oil pressure serving as source pressure of the PRI pressure and the SEC pressure. - The line pressure electric oil pump 111 is driven by an
electric motor 117. The line pressure electric oil pump 111 is operated for supplying the line pressure for example in a case where theengine 1 is stopped by idling stop control and accordingly the sourcepressure oil pump 101 is stopped. - The line
pressure adjusting valve 102 generates the line pressure by adjusting the oil pressure generated by theoil pump 101. The generation of the line pressure by theoil pump 101 includes generation of the line pressure on the basis of such an action of the linepressure adjusting valve 102. Oil released by the linepressure adjusting valve 102 at the time of pressure adjustment is supplied to the lock-up clutch 2 a, the lubrication system, and the cooling system via the low pressuresystem control valve 130. - The
pressure reduction valve 103 reduces the line pressure. The oil pressure reduced by thepressure reduction valve 103 is supplied to theline pressure SOL 104 and the forward/reverseswitching mechanism SOL 105. - The
line pressure SOL 104 is a linear solenoid valve and generates control oil pressure corresponding to a control electric current. The control oil pressure generated by theline pressure SOL 104 is supplied to the linepressure adjusting valve 102, and the linepressure adjusting valve 102 is activated in accordance with the control oil pressure generated by theline pressure SOL 104 to perform pressure adjustment. Therefore, it is possible to set a command value of line pressure PL by the control electric current to theline pressure SOL 104. - The forward/reverse
switching mechanism SOL 105 is a linear solenoid valve and generates oil pressure corresponding to a control electric current. The oil pressure generated by the forward/reverseswitching mechanism SOL 105 is supplied to theforward clutch 31 and thereverse brake 32 via themanual valve 108 activated in accordance with operation of a driver. - The shift
circuit pressure SOL 107 is a linear solenoid valve and generates oil pressure to be supplied to theshift circuit 110 in accordance with a control electric current. Therefore, it is possible to set a command value of shift circuit pressure by the control electric current to the shiftcircuit pressure SOL 107. The shift circuit pressure generated by the shiftcircuit pressure SOL 107 is supplied to ashift oil passage 106. The shift circuit pressure may be generated by a SOL adapted to generate control oil pressure corresponding to a control electric current, and a pressure adjusting valve adapted to generate control circuit pressure from the line pressure PL in accordance with the control oil pressure generated by the SOL. - The
shift circuit 110 includes ashift oil passage 106 connected to the linepressure oil passage 109 via the shiftcircuit pressure SOL 107, and ashift oil pump 112 placed in theshift oil passage 106. Theshift oil passage 106 provides communication between the PRI pulleyoil pressure chamber 41 c and the SEC pulleyoil pressure chamber 42 c. - The
shift oil pump 112 is an electric oil pump to be driven by anelectric motor 113. Theelectric motor 113 is controlled by thecontroller 10 via aninverter 114. The rotation direction of theshift oil pump 112 is switchable between the forward direction and the reverse direction. The forward direction mentioned above is the direction in which the oil is fed from the SEC pulleyoil pressure chamber 42 c side to the PRI pulleyoil pressure chamber 41 c side. The reverse direction is the direction in which the oil is fed from the PRI pulleyoil pressure chamber 41 c side to the SEC pulleyoil pressure chamber 42 c side. - When the
shift oil pump 112 is rotated in the forward direction, the oil in theshift oil passage 106 and the SEC pulleyoil pressure chamber 42 c is supplied to the PRI pulleyoil pressure chamber 41 c. Thereby, themovable pulley 41 b of thePRI pulley 41 is moved in the direction of coming close to the fixedpulley 41 a, and the groove width of thePRI pulley 41 is reduced. Meanwhile, themovable pulley 42 b of theSEC pulley 42 is moved in the direction of going away from the fixedpulley 42 a, and the groove width of theSEC pulley 42 is increased. At the time of forward rotation of theshift oil pump 112, the oil is supplied from the linepressure oil passage 109 to theshift oil passage 106 in such a manner that oil pressure of theshift oil passage 106 on the SEC pulleyoil pressure chamber 42 c side (hereinafter, also referred to as the “SEC side”) of the shift oil pump 112 (hereinafter, also referred to as the “SEC side oil pressure”) is not less than the command value of the shift circuit pressure. The command value of the shift circuit pressure is set in consideration with prevention of slip of thebelt 43, etc. Oil pressure of theshift oil passage 106 on the PRI pulleyoil pressure chamber 41 c side (hereinafter, also referred to as the “PRI side”) of theshift oil pump 112 will also be referred to as the PRI side oil pressure. - When the
shift oil pump 112 is rotated in the reverse direction, the oil flows out of the PRIpulley oil chamber 41 c. Thereby, themovable pulley 41 b of thePRI pulley 41 is moved in the direction of going away from the fixedpulley 41 a, and the groove width of thePRI pulley 41 is increased. Meanwhile, themovable pulley 42 b of theSEC pulley 42 is moved in the direction of coming close to the fixedpulley 42 a, and the groove width of theSEC pulley 42 is reduced. Although the SEC side oil pressure is increased by an inflow of the oil flowing out of the PRI pulleyoil pressure chamber 41 c, the SEC side oil pressure is controlled not to exceed the command value by the shiftcircuit pressure SOL 107. That is, in a case where the SEC side oil pressure exceeds the command value, the oil is discharged from theshift oil passage 106 via the shiftcircuit pressure SQL 107. Meanwhile, in a case where the SEC side oil pressure is less than the command value, the oil flows in from the linepressure oil passage 109 via the shiftcircuit pressure SOL 107. - As described above, in the continuously variable transmission of the first embodiment, shift is performed by the
shift oil pump 112 controlling a flow of the oil into and from the PRI pulleyoil pressure chamber 41 c. An outline of shift control will be described later. - Returning to
FIG. 1 , the vehicle further includes thecontroller 10. Thecontroller 10 is an electronic control device, and signals from a sensor andswitch group 11 are inputted to thecontroller 10. Thecontroller 10 is formed by a microcomputer including a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), and an input/output interface (I/O interface). Thecontroller 10 may be formed by plural microcomputers. - The sensor and
switch group 11 includes an accelerator pedal opening sensor adapted to detect an accelerator pedal opening of the vehicle, a brake sensor adapted to detect brake pedal force of the vehicle, a vehicle speed sensor adapted to detect vehicle speed Vsp, and an engine rotation speed sensor adapted to detect rotation speed NE of theengine 1. - The sensor and
switch group 11 further includes, for example, aPRI pressure sensor 115 adapted to detect the PRI pressure, aSEC pressure sensor 116 adapted to detect the SEC pressure, a PRIrotation speed sensor 120 adapted to detect input side rotation speed of thePRI pulley 41, a SECrotation speed sensor 121 adapted to detect output side rotation speed of theSEC pulley 42, a pumprotation speed sensor 118 adapted to detect rotation speed of theshift oil pump 112, and anoil temperature sensor 119 adapted to detect a temperature of the oil. The signals from the sensor andswitch group 11 may be inputted to thecontroller 10 via other controllers, for example. The same is applied to signals of information, etc. generated by other controllers on the basis of the signals from the sensor andswitch group 11. - The
controller 10 controls thehydraulic circuit 100 on the basis of the signals from the sensor andswitch group 11. Specifically, thecontroller 10 controls theline pressure SOL 104 and theshift circuit 110 shown inFIG. 2 . Thecontroller 10 is formed to further control the forward/reverseswitching mechanism SOL 105 and the shiftcircuit pressure SOL 107. - Upon controlling the
line pressure SOL 104, thecontroller 10 applies a control electric current corresponding to the command value of the line pressure PL to theline pressure SOL 104. - When executing the shift control, the
controller 10 sets a target speed ratio on the basis of the signals from the sensor andswitch group 11. Once the target speed ratio is determined, loop dimeters (target loop diameters) of thepulleys pulleys - In the
shift circuit 110, themovable pulley 41 b of thePRI pulley 41 is moved in accordance with the inflow and the outflow of the oil to and from the PRI pulleyoil pressure chamber 41 c by the shift oil pump, and accordingly, themovable pulley 42 b of theSEC pulley 42 is also moved. That is, there is a correlation between a movement amount of themovable pulley 41 b of thePRI pulley 41 and a movement amount of themovable pulley 42 b of theSEC pulley 42. - The
controller 10 operates theshift oil pump 112 in such a manner that a position of themovable pulley 41 b of thePRI pulley 41 is a position corresponding to the target speed ratio. Whether or not themovable pulley 41 b is at a desired position is determined by calculating an actual speed ratio from detection values of the PRIrotation speed sensor 120 and the SECrotation speed sensor 121 and determining whether or not the actual speed ratio matches with the target speed ratio. - The operation of the
shift oil pump 112 by thecontroller 10 is not limited to the time of shift. Even in a case where the target speed ratio is not changed but in a case where the oil is leaked out of the pulleyoil pressure chambers controller 10 operates theshift oil pump 112. In the first embodiment, such control for maintaining the target speed ratio is included in the shift control. - That is, the shift control of the first embodiment is feedback control of bringing the position of the
movable pulley 41 b of thePRI pulley 41 to a target position. An object to be controlled in the feedback control is not the oil pressure of the pulleyoil pressure chambers PRI pulley 41, in other words, the position of themovable pulley 41 b. - A sensor adapted to detect the position of the
movable pulley 41 b may be provided to determine whether or not themovable pulley 41 b is at a position corresponding to the target speed ratio. - In a so-called ignition-off state, both the source
pressure oil pump 101 and the line pressure electric oil pump 111 are stopped. Thus, no oil pressure is supplied to the linepressure oil passage 109 and the SEC pulleyoil pressure chamber 42 c. Therefore, for example, in a case where a long time passes after an end of driving the vehicle, the oil may be removed from the oil passages of the hydraulic circuit in a so-called no-oil state. When theengine 1 is started up in this no-oil state and the shift control is immediately started, theshift oil pump 112 is operated in a state where the oil is not filled in the linepressure oil passage 109 and theshift oil passage 106. Then, theshift oil pump 112 performs so-called idle pumping, and noises are generated due to the air entrainment described above. When theshift oil pump 112 is operated in the no-oil state, lubrication of a bearing portion becomes insufficient and there is a possibility that theshift oil pump 112 is deteriorated. - In the first embodiment, in order to suppress a harmful effect caused by start of the shift control in the no-oil state, the
controller 10 executes control to be described below. -
FIG. 3 is a flowchart showing a control routine of thehydraulic circuit 100 to be executed by thecontroller 10 at the time of start-up of the engine. The control routine is executed when theengine 1 is started up. - In Step S100, the
controller 10 determines whether or not the oil is filled in theshift oil passage 106 on the SEC side by a method to be described later. Thecontroller 10 repeats the determination of Step S100 until the oil is filled in theshift oil passage 106 on the SEC side, and when the oil is filled, starts up theshift oil pump 112 in Step S110. That is, in Step S100, by not permitting the operation of theshift oil pump 112 until the oil is filled in theshift oil passage 106 on the SEC side, thecontroller 10 restricts the operation of theshift oil pump 112. - Specific examples of the judging method of Step S100 include two examples as follows.
- Once the oil is filled in the
shift oil passage 106 on the SEC side, theshift oil pump 112 is rotated by an oil pressure difference between the SEC side and the PRI side without being driven by theelectric motor 113. When the rotation speed of theshift oil pump 112 detected by the pumprotation speed sensor 118 becomes higher than predetermined rotation speed (threshold value 1), thecontroller 10 determines that the oil is filled in theshift oil passage 106 on the SEC side. - The
threshold value 1 is set to be a value with which rotation of theshift oil pump 112 is obviously recognizable, for example, a few [rpm]. Theoretically, start of rotation of a rotation shaft of theshift oil pump 112 is required to be detected. Thus, a further smaller value may be set. However, in reality, the rotation shaft of theshift oil pump 112 may be moved by vibration of the vehicle, etc. Thus, in order to prevent erroneous determination caused by detecting motion due to such vibration of the vehicle, etc., thethreshold value 1 of the above magnitude is set. -
FIG. 4 is a timing chart of a case where the determination of the first example is performed. - When an operation of the source
pressure oil pump 101 is started at timing T1, oil pressure on the SEC side (SEC side actual oil pressure) then starts to be increased. Accordingly, theshift oil pump 112 starts to be rotated. At timing T2 where the rotation speed of theshift oil pump 112 exceeds thethreshold value 1, thecontroller 10 operates theelectric motor 113 for operating theshift oil pump 112. After that, in accordance with an increase of rotation of the sourcepressure oil pump 101 and theshift oil pump 112, the SEC side actual oil pressure and PRI side actual oil pressure are increased. - Once the oil is filled in the
shift oil passage 106 on the SEC side, the SEC side actual oil pressure is increased. When the increase of the SEC side actual oil pressure is detected by theSEC pressure sensor 116, that is, when the SEC side actual oil pressure exceeds predetermined oil pressure (threshold value 2), thecontroller 10 determines that the oil is filled in theshift oil passage 106 on the SEC side. - The threshold value 2 is set to be a value with which that the increase of the SEC side actual oil pressure is obviously recognizable. The threshold value 2 is set to have an enough magnitude in order to prevent erroneous determination as well as the
threshold value 1. -
FIG. 5 is a timing chart of a case where the determination of the second example is performed. - Both motions of the
source oil pump 101 and theshift oil pump 112 and changes in the SEC side actual oil pressure and the PRI side actual oil pressure are the same asFIG. 4 . However, the basis of determining the start of the operation of theshift oil pump 112 is the SEC side actual oil pressure being higher than the threshold value 2 at the timing T2. - As described above, in the first embodiment, after the source
pressure oil pump 101 is started up, the operation of theshift oil pump 112 is restricted until the oil is filled in theshift oil passage 106 on the SEC pulleyoil pressure chamber 42 c side of the shift oil pump (electric oil pump) 112. Thereby, theshift oil pump 112 is not rotated in the no-oil state, and it is possible to suppress generation of noises due to air entrainment and deterioration of theshift oil pump 112 due to rotation in a no-lubrication state. - In the first embodiment, as an example, when the rotation speed of the
shift oil pump 112 reaches the predetermined rotation speed, the operation of theshift oil pump 112 is permitted. That is, it is determined whether or not the oil is filled in theshift oil passage 106 on the SEC pulleyoil pressure chamber 42 c side of theshift oil pump 112 on the basis of the rotation speed of theshift oil pump 112. Thereby, even if thehydraulic circuit 100 does not include theSEC pressure sensor 116, it is possible to make proper determination. - In the first embodiment, as another example, when the oil pressure of the
shift oil passage 106 on the SEC pulleyoil pressure chamber 42 c side of theshift oil pump 112 reaches the predetermined oil pressure, the operation of theshift oil pump 112 is permitted. That is, it is determined whether or not the oil is filled in theshift oil passage 106 on the SEC pulleyoil pressure chamber 42 c side of theshift oil pump 112 on the basis of the pressure of the oil passage. Thus, it is possible to make precise determination. - The second embodiment is similar to the first embodiment in a point that an operation of a
shift oil pump 112 is restricted until oil is filled in ashift oil passage 106 on the SEC side. However, the second embodiment is different from the first embodiment in a point that a SEC side oil pressure command value is corrected while the operation of theshift oil pump 112 is restricted. Hereinafter, this different point will be mainly described. - When an
engine 1 is started up, acontroller 10 sets a target speed ratio on the basis of signals from a sensor andswitch group 11, and sets a SEC side oil pressure command value corresponding to the target speed ratio. The more the SEC side oil pressure command value is increased, the more an amount of oil flowing into theshift oil passage 106 via a shift circuitpressure solenoid valve 107 is increased and the more a time to the oil filling in theshift oil passage 106 on the SEC side is shortened. Thus, in the second embodiment, by increasing the SEC side oil pressure command value more than a value set corresponding to the target speed ratio, a time to restrict the operation of theshift oil pump 112 is shortened. -
FIG. 6 is a flowchart showing a control routine of ahydraulic circuit 100 to be executed by thecontroller 10 in the second embodiment. - In Step S200, the
controller 10 calculates a basic SEC side oil pressure command value. The basic SEC side oil pressure command value is the SEC side oil pressure command value corresponding to the target speed ratio. - In Step S210, the
controller 10 determines whether or not the oil is filled in theshift oil passage 106 on the SEC side. Contents and a method of determination are the same as Step S100 ofFIG. 3 . Thecontroller 10 executes processing of Step S210 in a case where the oil is filled in theshift oil passage 106 on the SEC side, and executes processing of Step S220 in a case where the oil is not filled. - In Step S220, the
controller 10 makes correction to increase the basic SEC side oil pressure command value, and makes the value after the correction a SEC side oil pressure command value. Specifically, for example, a table in which the lower an oil temperature is, the larger a correction amount is set as shown inFIG. 7 is created in advance and stored in thecontroller 10, and thecontroller 10 adds the correction amount determined on the basis of the table to the basic SEC side oil pressure command value. - After repeating the processing of Step S220 described above until the oil is filled in the
shift oil passage 106 on the SEC side, in Step S230, thecontroller 10 restores the SEC side oil pressure command value to the basic SEC side oil pressure command value calculated in Step S200. Thecontroller 10 starts up theshift oil pump 112 in Step S240. -
FIG. 8 is a timing chart of a case where the control described above is executed. Both motions of asource oil pump 101 and theshift oil pump 112 and changes in SEC side actual oil pressure and PRI side actual oil pressure are the same asFIG. 4 . The reference sign P1 in the figure denotes the basic SEC side oil pressure command value, and the reference sign P2 denotes a PRI side oil pressure command value. - As shown in
FIG. 8 , between timing T1 where the sourcepressure oil pump 101 is started up and timing T2 where theshift oil passage 106 on the SEC side is brought into an oil-filled state, the SEC side oil pressure command value is gradually increased by repeating the correction. Thereby, a gap between the timing T1 and the timing T2 is shorter than a case where the basic SEC side oil pressure command value is not increased and corrected. - The SEC side oil pressure command value is restored to the basic SEC side oil pressure command value at the timing T2.
- In Step S220 of
FIG. 6 , the SEC side oil pressure command value is set between the timing T1 and the timing T2 by correcting the basic SEC side oil pressure command value. However, the present invention is not limited to this. For example, a table in which the SEC side oil pressure command value is set in accordance with the oil temperature as shown inFIG. 9 may be created in advance and stored in thecontroller 10, and thecontroller 10 may directly calculate the SEC side oil pressure command value from the table. The case where the SEC side oil pressure command value is gradually increased from the timing T1 to the timing T2 is described above. However, the present invention is not limited to this. For example, at the time point of the timing T1, the SEC side oil pressure command value may be set to be the SEC side oil pressure command value of the timing T2 ofFIG. 8 and this may be maintained to the timing T2. - As described above, in the second embodiment, while the operation of the
shift oil pump 112 is restricted, target oil pressure of theshift oil passage 106 on the SEC pulleyoil pressure chamber 42 c side of theshift oil pump 112 is set to be higher than a case where the operation of theshift oil pump 112 is not restricted. Thereby, increasing speed of the SEC pressure is increased. Thus, the time to restrict the operation of theshift oil pump 112 is shortened more than a case where the target oil pressure is not increased. As a result, it is possible to shorten a time required for obtaining a shiftable state more than a case where the target oil pressure is not increased. - In the second embodiment, the lower the oil temperature is, the higher the target oil pressure while the operation of the
shift oil pump 112 is restricted is set. The lower the temperature is, the greater friction of thepumps - In the first embodiment and the second embodiment, the operation of the
shift oil pump 112 is restricted until the oil is filled in theshift oil passage 106 on the SEC side. Meanwhile, in the third embodiment, after oil is filled in ashift oil passage 106 on the SEC side, an operation of ashift oil pump 112 is further restricted until oil pressure of theshift oil passage 106 on the PRI side reaches predetermined pressure. -
FIG. 10 is a flowchart showing a control routine of the third embodiment described above. - In Step S300, a
controller 10 determines whether or not actual oil pressure of theshift oil passage 106 on the PRI side becomes higher than athreshold value 3. Thethreshold value 3 is PRI pressure determined on the basis of a target speed ratio. - When the actual oil pressure of the
shift oil passage 106 on the PRI side becomes higher than thethreshold value 3, thecontroller 10 starts up theshift oil pump 112 in Step S310. -
FIG. 11 is a timing chart of a case where the control routine ofFIG. 10 is executed. - After a source
pressure oil pump 101 is started up at timing T1, SEC side actual oil pressure starts to be increased at timing T2. In accordance with an increase of the SEC side actual oil pressure, theshift oil pump 112 starts to be rotated by a pressure difference between the SEC side and the PRI side. Theshift oil pump 112 is rotated by the pressure difference described above. Thus, when the SEC side actual oil pressure is continuously increased, rotation speed of theshift oil pump 112 is also increased. Once PRI side actual oil pressure reaches the PRI pressure (threshold value 3) determined on the basis of the target speed ratio at timing T3, thecontroller 10 starts up theshift oil pump 112. - In such a way, when the operation of the
shift oil pump 112 is restricted until the PRI side actual oil pressure reaches the PRI pressure determined on the basis of the target speed ratio, it is possible to reduce electric power consumed by theshift oil pump 112 until the PRI pressure is increased to the pressure determined on the basis of the target speed ratio. That is, in comparison to the first embodiment and the second embodiment, it is possible to reduce the consumed electric power of theshift oil pump 112. - In the third embodiment, correction of SEC side command oil pressure may be performed as well as the second embodiment. In this case, as shown in
FIG. 12 , the correction of the SEC side command oil pressure is continued until the timing T3. - As described above, in the third embodiment, even after the oil is filled in the
shift oil passage 106 on the SEC pulleyoil pressure chamber 42 c side of theshift oil pump 112, the operation of theshift oil pump 112 is restricted until the actual oil pressure of theshift oil passage 106 on the PRI pulleyoil pressure chamber 41 c side of theshift oil pump 112 reaches command oil pressure. Thereby, it is possible to reduce the electric power consumed by theshift oil pump 112 until the PRI pressure is increased to the pressure determined on the basis of the target speed ratio. - In the embodiments described above, the configuration in which as an oil pump adapted to supply source pressure, the mechanical oil pump (source pressure oil pump 101) and the electric oil pump (line pressure electric oil pump 111) are used together is described. However, any one of the oil pumps may be provided.
- Embodiments of the present invention are described above. However, the above embodiments do not intend to limit the technical scope of the present invention to the specific configurations of the above embodiments but only indicate part of application examples of the present invention.
- While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.
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JP2016166760A JP6859631B2 (en) | 2016-08-29 | 2016-08-29 | Control method and control device for continuously variable transmission |
PCT/JP2017/028628 WO2018043052A1 (en) | 2016-08-29 | 2017-08-07 | Control method and control apparatus for continuously variable transmission |
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2016
- 2016-08-29 JP JP2016166760A patent/JP6859631B2/en active Active
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2017
- 2017-08-07 CN CN201780051737.8A patent/CN109642663B/en active Active
- 2017-08-07 WO PCT/JP2017/028628 patent/WO2018043052A1/en active Application Filing
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US10527164B2 (en) * | 2016-11-24 | 2020-01-07 | Nissan Motor Co., Ltd. | Method for controlling continuously variable transmission and continuously variable transmission system |
US20240060556A1 (en) * | 2021-02-22 | 2024-02-22 | Jatco Ltd | Sensor arrangement structure |
US12018742B2 (en) * | 2021-02-22 | 2024-06-25 | Jatco Ltd | Sensor arrangement structure |
US20220389975A1 (en) * | 2021-06-08 | 2022-12-08 | Dana Belgium N.V. | Vehicle transmission with disconnect devices |
US11933370B2 (en) * | 2021-06-08 | 2024-03-19 | Dana Belgium N.V. | Vehicle transmission with disconnect devices |
Also Published As
Publication number | Publication date |
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JP6859631B2 (en) | 2021-04-14 |
CN109642663A (en) | 2019-04-16 |
JP2018035813A (en) | 2018-03-08 |
US10711884B2 (en) | 2020-07-14 |
CN109642663B (en) | 2020-10-23 |
WO2018043052A1 (en) | 2018-03-08 |
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